Minimally invasive surgery system

ABSTRACT

A minimally invasive surgery system including a robot, a cannula assembly and a computer system. The robot has at least one movable robot arm and the cannula assembly is detachably mounted to the robot arm. The cannula assembly includes a cannula and a pattern generating member. The cannula has a distal end and a proximal end with a flange portion and an elongate cannula shaft portion extending from the proximal end to the distal end and an access port through the elongate cannula shaft portion. The pattern generating member includes a pattern light source and a projector temporarily or permanently fixed to the cannula shaft portion. The pattern light source is operatively connected to the projector for projecting a light pattern. The computer system is configured for in real time receiving image data representing light pattern reflections from a surgical surface and for determining a real-time spatial position of the cannula assembly relative to the surgical surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 15/717,088 entitled “A Minimally Invasive Surgery System” filed Sep. 27, 2017, which is a continuation in part of U.S. patent application Ser. No. 15/589,476 entitled “Cannula Assembly Kit” filed May 8, 2017, which is a continuation of International Application PCT/DK2016/050234, with an international filing date of Jul. 1, 2016 and claiming priority from PA 2015 70483 DK of Jul. 21, 2015.

TECHNICAL FIELD

The invention relates to a minimally invasive surgery system comprising a robot, a cannula assembly and a computer system, suitable for performing robotic surgery or robot assisted surgery.

BACKGROUND ART

Minimally invasive surgery has been used increasingly in recent years due to the benefits compared to conventional open surgery as it reduces the trauma to the patient tissue, leaves smaller scars, minimizes post-surgical pain and enables a faster recovery of the patient.

For example, in laparoscopic surgery, which is a typical form of minimally invasive surgery, the surgeon accesses a body cavity, such as the abdominal or pelvic cavity, through a series of small incisions. A laparoscope is inserted through an incision, and conventionally connected to a monitor, thereby enabling the surgeon to see the inside of the abdominal or pelvic cavity. In order to perform the surgical procedure, surgical instruments are inserted through other incisions. In addition, the body cavity around the surgical site is inflated with a fluid, preferably gas e.g. carbon dioxide in order to create an ‘air’ space within the cavity to make space for the surgeon to view the surgical site and move the laparoscopic instruments.

Invasive surgeries are generally performed through rather small openings in a patient's skin and the surgical site is visualized for the surgeon by inserting a camera, such as an endoscope into the body cavity and displaying the images on a screen.

In order to improve the vision for surgeon, in particular to make it easier for the surgeon to determine the sizes of various organs, tissues, and other structures in a surgical site, several in-situ surgical metrology methods have been provided in the prior art. Different types of optical systems have been applied to provide an improved vision of the surgical site, which is approaching a 3D vision.

US2014276097 describes a system and method for performing optical measurements within a body cavity during minimal surgery. The system comprises a light source configured to emit a light beam, a first pattern generator defining a first longitudinal axis and configured to project a first generated pattern, and a second pattern generator defining a second longitudinal axis and configured to project a second generated pattern. The first and second generated patterns have different angular divergences. The first pattern generator is a diffractive circle pattern generator, whereas the second pattern generator is a diffractive cross pattern generator. Adjustment of the first and second generated patterns with respect to each other causes the system to serve as an optical ruler for performing the optical measurements when the first and second generate patterns overlap or coincide with each other at certain points.

EP 2630915 describes a light instrument for use in minimally invasive surgery, where the instrument includes an elongate tubular member and a metrology system mounted on the elongate tubular member. The metrology system includes a mask, a zoom lens assembly and a light element arranged such that the light element propagates light beams through the mask and the zoom lens assembly to project the patterns of the mask onto the surgical site of interest to provide markings as references used for measuring by the surgeon.

US 2013/0296712 describes an apparatus for determining endoscopic dimensional measurements, including a light source for projecting light patterns on a surgical sight including shapes with actual dimensional measurements and fiducials, and means for analyzing the projecting light patterns on the surgical site by comparing the actual dimensional measurements of the projected light patterns to the surgical site.

WO 2013/163391 describes at system for generating an image, which the surgeon can use for measuring the size of or distance between structures in the surgical field by using an invisible light for marking a pattern to the surgical field.

The system comprises a first camera; a second camera; a light source producing light at a frequency invisible to human eye; a dispersion unit projecting a predetermined pattern of light from the invisible light source; an instrument projecting the predetermined pattern of invisible light onto a target area; a band pass filter directing visible light to the first camera and the predetermined pattern of invisible light to the second camera; wherein the second camera images the target area and predetermined pattern of invisible light, and computes a three-dimensional image.

DISCLOSURE OF INVENTION

In an embodiment is provided a solution for performing robotic surgery or robot assisted surgery with high accuracy.

The solution may provide good visibility of a body cavity during minimally invasive surgery in particular with respect to providing good visual information to the surgeon about the position of the surgical instrument relative to the surgical site.

In an embodiment is provided a tool for use in minimally invasive surgery, which tool can increase the visibility of a body cavity to thereby make it simpler for a surgeon to determine the position of a surgical instrument relative to the surgical site and thereby to increase the surgeon's control of movements of the surgical instrument relative to the surgical site.

In an embodiment is provided a tool for providing an increased visibility of the position of a surgical instrument relative to the surgical site, which tool is simple to use and can be produced at an adequate cost.

It has been found that the invention or embodiments thereof have a number of additional advantages, which will be clear to the skilled person from the following description.

It has been found that by using a cannula assembly kit of the invention an operator, such as a surgeon, a robot and/or a surgeon assisted robot can obtain a very good or even excellent determination and/or visibility of the position of a surgical instrument relative to the surgical site or a point or area at the surgical site, which thereby results in an increased control of the instrument, which both reduce the risk of making mistakes during the surgery and at the same time may reduce the required time for a minimal surgery procedure.

In order for an operator to move a surgical instrument in a relatively gentle way, it is standard to provide a cannula (sometimes also called a sleeve) to provide an access port through the incision. The cannula functions as a portal for the subsequent placement of a surgical instrument, such as graspers, scissors, staplers, etc. Usually the cannula is inserted through the incision by using an obturator which is temporarily inserted through the access port of the cannula. A set comprising an obturator and a cannula is called a trocar. The obturator may be a metal or plastic sharpened or non-bladed tip. Where the obturator comprises a sharp tip, the tip may be used by the operator to make the incision. Where the obturator is of the non-bladed tip type, the operator uses a scalpel to cut through at least a skin top layer where after the trocar can be pressed through the incision. When the trocar has been pressed through the incision, the obturator is removed and the cannula now forms an access port. The cannula usually comprises one or more seals to seal against gas slip-out and to accommodate an instrument.

The cannula assembly kit advantageously comprises one or more seals e.g. such as the seals described in the article “Trends in Laparoscopy: Sealing Technology” Posted on Medical Device And Diagnostic Industry www.mddionline.com by mddiadmin on Aug. 1, 2009.

The terms distal and proximal should be interpreted in relation to the orientation of the cannula.

The term “cannula assembly” is herein used to designate the assembled cannula assembly kit. The cannula assembly may thus include any of the disclosed cannula assembly kits in assembled condition. The term “visibility” and corresponding terms thereof means “determination” or “determine” when applied about a robot.

The phrase “distal to” means “arranged at a position in distal direction to”. The phrase “distally arranged” means arranged distally to the distal end of the surgical instrument.

The term “substantially” should herein be taken to mean that ordinary product variances and tolerances are comprised.

The term “about” is generally used to ensure that what is within measurement uncertainties are include. The term “about” when used in ranges, should herein be taken to mean that what is within measurement uncertainties are included in the range.

The phrase “real time” is herein used to mean the time it requires the computer to receive and process constantly changing data optionally in combination with other data, such as predetermined data, reference data, estimated data which may be non-real time data such as constant data or data changing with a frequency of above 1 minute to return the real time information to the operator. “Real time” may include a short delay, such as up to 5 seconds, preferably within 1 second, more preferably within 0.1 second of an occurrence.

The Term “operator” is used to designate a surgeon or a robotic surgeon i.e. a robot programmed to perform a laparoscopic procedure on a patient and/or a surgeon assisted robot.

The term “surgical instrument” means herein a laparoscopic tool comprising a surgical tool adapted for performing surgery onto the tissue within the surgery cavity e.g. a grasper, a suture grasper, a cutter, a sealer, a stapler, a clip applier, a dissector, scissors, shears, a suction instrument, a clamp instrument, an electrode, a coagulation device, a curette, ablators, scalpels, a needle holder, a needle driver, a spatula, forceps, a biopsy and retractor instrument or a combination thereof.

It should be emphasized that the term “comprises/comprising” when used herein is to be interpreted as an open term, i.e. it should be taken to specify the presence of specifically stated feature(s), such as element(s), unit(s), integer(s), step(s) component(s) and combination(s) thereof, but does not preclude the presence or addition of one or more other stated features.

Throughout the description or claims, the singular encompasses the plural unless otherwise specified or required by the context.

Statements of “relative distance”, “relative position” and “relative spatial position” are used interchangeable. A relative distance between two elements should be interpreted to mean a relative distance between a least a portion e.g. a specific part of the respective elements. The relative distance between an element and a surgical surface should be interpreted to mean a relative distance between a least a portion e.g. a specific part of the element, such as a tip of a surgical tool and the surgical surface unless otherwise specified or clear from the context.

In an embodiment the invention relates to minimally invasive surgery system comprising a robot, a cannula assembly and a computer system. The robot comprises at least one movable robot arm.

The robot may comprise 2, 3, 4 or more arms. The cannula assembly is detachably mounted to the robot arm. Advantageously the robot arm comprises a mounting bracket for rigidly mounting the cannula assembly to the robot arm. In an embodiment the cannula assembly and the robot arm is mounted to each other via a mounting arrangement which allows the cannula and the robot arm to rotate and or tilt relative to each other. In an embodiment the mounting arrangement between the cannula assembly and the robot arm allow the cannula assembly and the robot arm to be displaced relative to each other.

The cannula assembly may be in the form of an assembled cannula assembly kit as described herein. And comprises a cannula and a pattern generating member. The cannula has a distal end and a proximal end with a flange portion and an elongate cannula shaft portion extending from the proximal end to the distal end and an access port through the elongate cannula shaft portion. The pattern generating member comprises a pattern light source and a projector temporarily or permanently fixed to the cannula shaft portion, wherein the pattern light source is operatively connected to the projector for projecting a light pattern. The computer system is configured for in real time receiving image data representing light pattern reflections from a surgical surface and for determine a real-time spatial position of the cannula assembly relative to the surgical surface. Preferably the computer system is configured for determine a real-time spatial position of the projector of the cannula assembly relative to the surgical surface.

The image data may be generated by any camera e.g. an external camera, The camera may e.g. be a camera of an endoscope,

The computer system may be a single computer unit or it may advantageously comprise two or more computer units in data communication e.g. by wire or wireless. The computer system or a part thereof may be integrated with or be connected to the robot.

In an embodiment the minimal invasive surgery system comprises a camera configured for acquiring images and generate the image data representing at least a part of the image and for transmitting the image data in real time to the computer system. The camera may be fixed to the robot e.g. to the same arm as the cannula assembly or preferably to another robot arm. In an embodiment the camera is mounted to or integrated with the robot. In an embodiment the camera is mounted to or integrated with a scope, such as an endoscope.

In an embodiment the real-time spatial position of the projector of the cannula assembly and the real-time position of the camera may be applied to generate a 3D model of a surgical surface in real-time by using the real-time spatial position of the projector and the real-time spatial position of the camera. This determination may e.g. be performed by the computer system using triangulation to calculate the distance from the camera to each pixel of the pattern reflected from the surgical surface, thereby generating a point cloud representing a 3D model of the surgical surface. Advantageously the minimally invasive surgery system comprises a surgical instrument and preferably the computer system is configured for in real time receiving the image data representing the reflections of the light pattern projected from projector of the cannula assembly to determine the spatial position of the cannula assembly relative to the surgical surface and receiving or determining the real time relative position between the cannula assembly and the surgical instrument and applying these relative positions to determine a real-time spatial position of at least a portion of the surgical instrument relative to the surgical surface when at least the portion of the surgical instrument is inserted through the access port of the cannula. The computer system is advantageously adapted to determine a real-time spatial position of surgical tool tip of the surgical instrument relative to the surgical surface.

The surgical instrument may advantageously be detachably mounted to a robot arm e.g. the same robot arm to which the cannula assembly is mounted or to another robot arm. Advantageously the cannula assembly and the surgical instrument are mounted to the same robot arm. The computer system is preferably configured for determining a real time relative position between the cannula assembly and at least a portion of the surgical instrument. Thereby both the cannula assembly real time position relative to the surgical surface and the surgical instrument real time position relative to the cannula assembly may be determined with a high accuracy. The computer may be configured for correlating the two sets of position data to determine (e.g. by deducting or otherwise calculating) the real-time position of the surgical instrument relative to the surgical surface. The real-time relative position may be provided as a real-time distance, such as a real-time minimum distance.

Advantageously the computer system is configured for continuing determining a real-time spatial position of a portion (e.g. a tool tip) of the surgical instrument relative to the surgical surface from the determined a real-time spatial position of the cannula assembly relative to the surgical surface and the determined a real time relative position between said cannula assembly and the portion of said surgical instrument, wherein the real- time determinations is continued for a period of time comprising at least one minute, such as at least 5 minute or longer.

Data representing the position of the surgical instrument relative to the surgical surface may be used for a variety of applications that may improve surgical procedures performed using the minimally invasive surgery system, such as applications relating to semi-autonomous and autonomous robotic surgery, such as determining safe or unsafe movements of the surgical instruments or the tool thereof which movements may be reported to the operator. The data generated by the computer may be collected and used for machine learning purposes to determine optimal and non-optimal movements of the surgical tools relative to the surgical surface in order for an operator to perform safe surgery with a reduced risk of surgical errors.

In an embodiment the surgical instrument comprises a mounting portion (sometimes referred to as a handle portion), a body portion with a straight position and having a length and an axis and a surgical tool e.g. as described herein.

The body portion is advantageously interconnecting the mounting portion and the surgical tool. The surgical instrument is advantageously mounted to the robot arm via said mounting portion. The mounting portion is advantageously rigidly mounted to a rail bracket integrated with or fixed to the robot arm, such that the mounting portion is displaceable in a direction of the body portion when in its straight position. In an embodiment the body portion is straight and stiff, thus it is always in straight positon. In an embodiment the body portion is bendable in one or more joints. Advantageously the one or more joints is positioned closer to the surgical tool than to the mounting portion. In an embodiment a length section of the body portion closer to the surgical tool, preferably adjacent to the surgical tool, is an articulated body length section comprising a plurality joints forming an articulated body portion length section.

The mounting portion of the surgical instrument may comprise electrical connection allowing the robot and optionally the computer system controlling the movements and bends of the joint(s) or articulated body portion length section of the body portion.

In an embodiment the cannula assembly and the surgical instrument are mounted to at least one robot arm to provide that the axis of the body portion in straight position is coincident with the access port of the cannula assemly.

In an embodiment the robot is configured for inserting the surgical tool though the access port of the cannula assembly.

In an embodiment the surgical instrument is mounted to the robot arm via the mounting portion and the robot is configured for moving the mounting portion relative to the cannula e.g. to provide that the mounting portion is displaced in a direction parallel and/or coincident with the straight body portion of the surgical instrument. Thereby the surgical tool can be moved closer to and further from the surgical surface e.g. during surgery.

The minimally invasive surgery system preferably comprises calibration means for calibration of the relative position of the surgical tool and the cannula.

The surgical tool may for example comprise a calibration location e.g. a tip of the tool or another location of the tool and the computer is configured for perform a calibration of the displacement of the surgical tool relative to the cannula assembly to determine the relative position between the cannula or a location thereof e.g. the projector and the calibration location of the surgical tool.

In an embodiment the surgical tool comprises a calibration location and the computer is configured for determining the relative position of the surgical tool relative to the cannula assembly.

The robot may advantageously comprise at least one encoder configured for tracking the real-time movement of the surgical tool and for conferring (e.g. by transmitting data representing) the tracked movements in real time to the computer system. The at least one encoder may include one or more rotary or linear encoders positioned on one or more robot arms.

The encoder(s) may for example include one or more of at least one type of encoder comprising mechanical, magnetic, optical, capacitive encoder type or any combinations thereof.

In an embodiment the cannula assembly and the surgical instrument is mounted to the same robotic arm and the minimally invasive surgery system is configured for performing an initial displacement calibration of the surgical tool and the cannula assembly to thereby determine the relative position between the surgical tool and the cannula assembly. By continuously tracking the motion (kinematic data) of the surgical tool through, for example rotary or linear encoders on the robot arm (types of encoders: mechanical, magnetic, optical, capacitive) the change in relative position between the cannula assembly and the surgical tool may be calculated in real-time. The relative postion between the cannula assembly and the surgical tool may also be tracked using other distance and positioning sensors, such as Time-Of-Flight sensors, magnetic sensors or structured light sensors or any other sensors and combinations thereof.

The computer system may advantageously be configured for controlling movements of one or more arms of the robot, preferably including displacement of elements, such as the mounting portion of the surgical instrument or the mounting potion of cannula assembly. In an embodiment the mounting of the mounting portion to the robot arm also provides an electrical connection between the robot and the surgical tool enabling the computer system to control the operation of the surgical instrument, preferably including controlling movements of the surgical tool and parts thereof and movement of the body portion e.g. including bending, tilting, rotating and/or twisting thereof. In an embodiment the mounting of the mounting portion to the robot arm also provides an electrical connection between the robot and the cannula assembly enabling the computer system to control the operation of the cannula assembly, preferably including controlling movements of the cannula assembly e.g. including bending, tilting, rotating and/or twisting thereof.

In an embodiment the computer system is configured for receiving information of any changes to the movement of the surgical tool. This may for example comprise any tool movement that influence the orientation and distance of the tool relative to the surgical surface—thereby calculating changes to the relative position between any part of the surgical tool and the surgical surface due to said tool movement.

In an embodiment the computer system is configured for receiving or acquiring data representing operation of the surgical instrument.

The computer system may e.g. receive such data from encoder(s) or alternative tracking sensor(s) as disclosed above. In an embodiment the computer system may acquire or determine data representing operation of the surgical instrument from data representing an operation position of the robot e.g. in real-time. Where the computer system is configured for operating the robot, the operation position of the robot may be known to the computer system.

In an embodiment the surgical tool comprises at least one movable part, the movable part being movable relative to at least one other part of the surgical tool, by a movement comprising at least one of displacing, twisting, rotating, pivoting or tilting and wherein the computer system is configured for receiving or acquire data representing the movements of the part(s).

The computer system may for example be configured to receive information from the robot relating to operation of the surgical instrument—e.g. to determine if two grasper blades of the surgical tool have shifted from a closed to an open position, thereby calculating changes to the relative position between the surgical tool and the surgical surface due to said change of grasper blade position.

In an embodiment at least one movable part has a tip and the computer system is configured for receiving or acquire data representing the movements of the tip and for calculate changes to the relative position between the distal tip of the surgical tool and the surgical surface due to the movements. This determination may advantageously comprise determining a real-time spatial position B of the projector of the cannula assembly relative to the surgical surface, determining a real time relative position A between the projector of the cannula assembly and the distal tip of the surgical tool and from A and B determining the real-time spatial position of the distal tip of the surgical instrument relative to the surgical surface. The computer may advantageously be configured for calculate changes to the determined relative position between the distal tip of the surgical tool and the surgical surface using the data representing the movements of the tip.

In an embodiment the computer system is configured to receive information relating to any movements of a surgical tip of the surgical tool—e.g. any changes in tilt or rotation—and to calculate changes to the relative position between the distal tip of the surgical tool and the surface due to said tilt or rotation.

In an embodiment the computer system is configured for generating, receiving or acquiring data representing the real time relative position of the mounting portion of the surgical instrument and the cannula assembly and the computer system is configured for applying the data representing the real time relative position of the mounting portion of the surgical instrument and the cannula assembly in the determination of the a real-time spatial position of the cannula assembly relative to the distal tip of the surgical tool.

In an embodiment the computer system is configured for determine a real-time spatial position of the distal tip of the surgical tool relative to the surgical surface.

In an embodiment the minimal invasive surgical system is also configured to receive information about the position of the robot arm and the cannula assembly—the computer system may be programmed to use this position information to improve the determination of the real-time position of the projector of the cannula assembly based on the images data.

It should be understood that the computer system may receive other data for improving the real time determination(s) e.g. data representing the surgical surface, such as topological data or other data e.g. acquired by scanning of the surgical surface.

In an embodiment the cannula assembly kit is adapted to constitute a part of a trocar suitable for use in minimally invasive surgery. The cannula assembly kit comprises a cannula and a pattern generating member. The cannula has a distal end and a proximal end and comprises an elongate cannula shaft portion extending from the proximal end to the distal end and an access port through said elongate cannula shaft portion, such that a surgical tool of a surgical instrument can be inserted through the access port.

Advantageously the cannula assembly kit comprises a flange portion at its proximal end for holding the cannula assembly kit in position after it has been inserted through an incision.

In use, the distal end of the cannula shaft portion is inserted through the incision e.g. together with a distal end of an obturator and the proximal end optionally comprising a flange portion remains outside the incision to ensure a safe positioning of the cannula. The flange portion may have any shape or size. The cannula shaft portion may have any cross-sectional shapes e.g. round, oval or angular for example as the cross-sectional shapes of prior art cannulas.

In the following the cannula assembly kit is described with a flange portion at its proximal end, however it should be understood that such flange portion may be omitted, in particular where the cannula assembly kit is part of or adapted to be handled by a robot as described below.

The pattern generating member comprises a pattern light source and a projector, wherein the pattern light source is operatively connected to the projector for projecting a light pattern. At least the projector of the pattern generating member is configured to be at least temporarily fixed to the cannula shaft portion of said cannula. Preferably at least the projector of the pattern generating member is configured to be fixed to the cannula shaft portion of said cannula to form a substantially rigid connection between said projector and said cannula shaft portion.

The term “access port” means a port through which a surgical instrument can be inserted. The access port may comprise a seal or an insulation, a lid and/or similar which fully or partly locks or fills out the access port when the surgical instrument is not inserted in the access port. The seal, insulation and/or seal ensure that undesired amounts of gasses do not escape and deflate the body cavity. When a surgical instrument is not inserted in the access port, the seal or the insulation advantageously seals against undesired outslip of gas.

The term “rigid connection” means a connection, which ensures that the relative position between rigidly connected elements is substantially constant during normal use.

Although the assembly kits of the invention are mainly described in an unassembled state, the invention should be interpreted to also include the assembled corresponding version(s) of the assembly kits.

In use the projector may be moved in a correlated way with at least some of the movement of a surgical instrument inserted through the access port of the cannula shaft portion and thereby images of the projected light pattern from the projector will change, thereby providing the operator with visual information about the position of the projector relative to the surgical site.

Advantageously at least the projector of the pattern generating member is configured to be at least temporarily fixed to the cannula shaft portion of the cannula, such that any lateral movement of a surgical tool of a surgical instrument inserted through the access port results in a correlated movement of the projector and thereby a correlated change of the reflections of the projected light pattern which can be imaged onto a screen via a camera e.g. of a scope, such as an endoscope. The change of the reflected pattern is herein also referred to as the recorded or recordable pattern.

The phrase “a correlated change” or “a correlated movement” means a change or movement, which corresponds to the lateral movements of the surgical instrument such that a given lateral movement of the surgical instrument results in a given and/or corresponding change or movement of respectively the projected light pattern and the projector. In an embodiment the movement of the surgical instrument may result in a gearing of the change or movement of respectively the projected light pattern and the projector. A change of the projected light pattern is herein used to mean a change of reflections of the projected light seen on a surface arranged distal to the cannula.

The pattern may reach an inner wall of a body cavity in which the minimally invasive surgery is performed—herein also referred to as the surgical site.

The surgical site often comprises a very curved and uneven surface, which will be visible from the shape of the pattern as it is reflected on the surgical site. The projector may project the light pattern on an area of the surgical site such that the contours and/or the topography of the surgical site and the position of the surgical instrument can be deduced by a computer (?) the operator based on indirect vision of the light pattern.

The surgical site may comprise one or more sensitive point or areas, which advantageously may be protected against damage, such a one or more veins and/or nerves. By using an embodiment of the cannula assembly kit, the operator may ensure that such sensitive point or areas are not accidently damaged by a surgical instrument inserted in to the access port of the cannula.

In an embodiment at least the projector of the pattern generating member is configured to be at least temporarily fixed to the cannula shaft portion of the cannula, such that any tilting movements of the cannula result in a correlated movement of the projector and thereby a correlated change of the reflections of the projected light pattern. In an embodiment the reflections of the projected light pattern is received by a camera. The camera may in an embodiment be mounted to or form part of the cannula. The camera may optionally be mounted at the distal end of the cannula arranged for monitoring reflected light. By having the camera fixed to the cannula or integrated with the cannula any risk of damaging tissue by the camera may be reduced. Further, the camera need not be held by the operator or an assisting operator. In an embodiment the camera is mounted to be pivotally moved relative to the shaft portion of the cannula. Thereby the operator can angle the camera in any desired direction.

In an embodiment the camera is mounted to a scope, such as an endoscope. The camera may transmit the recorded signal to a screen and/or transmit the recorded signal to a robot configured for maneuvering the surgical instrument. In an embodiment the camera forms part of the robot configured for maneuvering the surgical instrument. The recorded signal may preferably be transmitted in real life speed to ensure that the time delay becomes as small as possibly.

In an embodiment the camera or the computer system is configured for transmitting the recorded signal in real life to a screen which is visible to a surgeon or an observer of the minimally invasive surgery.

In an embodiment the projector of the pattern generating member is configured to be at least temporarily fixed to the cannula shaft portion of the cannula such that at least a portion of the light pattern is projected in a distal direction.

Distal direction means herein in a direction, which is parallel with or up to 90 degrees in any direction relative to a center axis of the access port or—where the center axis is not straight—relative to tangent to the center axis at the access port exit. In an embodiment the term “distal direction is used to mean a direction, which is parallel with or up to 90 degrees in any direction relative to a center axis of the access port or—where the center axis is not straight—relative to tangent to the center axis at the access port exit. Advantageously at least a portion of the light pattern is projected in a direction which is parallel with or up to 30 degree relative to a direction parallel with the center axis of the access port or relative to tangent to the center axis of the access port at the access port exit and preferably at least a portion of the light pattern is projected in a direction which is parallel with or up to 15 degree relative to a direction parallel with the center axis of the access port or tangent to the center axis at the access port exit, such as up to 10 degree relative to a direction parallel with the center axis of the access port or tangent to the center axis at the access port exit.

The access port exit is the exit of the access port at the distal end of the cannula shaft portion.

As it will be further explained below, in an embodiment the cannula is bendable and/or bent and in such situations the distal direction should be determined in respect to the distal end of the cannula. For certain surgical procedures, it is desired that the cannula is bent or bendable to a very high degree e.g. up to 180 degrees, such as up to about 90 degrees. The distal direction is determined as the direction parallel to tangent to the center axis of the access port at the access port exit ±up to 45 degrees, such as ±up to 30 degrees, such as ±up to 15 degrees. Where the cannula is bendable and/or bent and at the same time straight in an end section comprising the access port exit, the tangent to the center axis of the access port at the access port exit is identical to the center axis at the end section comprising the access port exit.

In an embodiment the projector of the pattern generating member is configured to at least temporarily fixed to the cannula shaft portion of the cannula such that at least a portion of the light pattern is projected in a proximal direction, such as in a direction opposite to a distal direction. This embodiment is in particular advantageous where the target of the surgical site is laterally positioned relative to a surgical instrument inserted through the access port.

In an embodiment the projector of the pattern generating member is configured to be at least temporarily fixed at the distal end of the cannula shaft portion.

Advantageously the distal end of the cannula shaft portion has a distal access port exit and comprises an end edge in the vicinity of the distal access port exit. The end edge optionally frames the distal access port exit. The projector of the pattern generating member is configured to be at least temporarily fixed at the end edge, preferably to form a rigid connection thereto. The projector is preferably arranged for projecting the light pattern in a distal direction, preferably such that at least a portion of the light pattern is projected in a direction, which is parallel with or up to 45 degrees relative to a direction parallel with the center axis of the access port. In an embodiment the projector is arranged for projecting the light pattern in a distal direction, which is parallel with or up 30 degrees relative to a direction parallel with the center axis of the access port, such as in a direction which is parallel with or up to 15 degrees relative to a direction parallel with the center axis of the access port, such as in a direction which is parallel with or up to 10 degrees relative to a direction parallel with the center axis of the access port.

In an embodiment at least a portion of the light pattern is projected in a direction which is parallel with or up to 45 degrees relative to a direction parallel with tangent to the center axis of the access port at the access port exit. In an embodiment the projector is arranged for projecting the light pattern in a distal direction, which is parallel with or up 30 degrees relative to tangent to the center axis of the access port at the access port exit, such as in a direction which is parallel with or up to 15 degrees relative to tangent to the center axis of the access port at the access port exit, such as in a direction which is parallel with or up to 10 degrees relative to tangent to the center axis of the access port at the access port exit.

The end edge is advantageously an edge extending between an inner surface defining the access port and an outer surface of the cannula shaft portion at the distal end of the cannula shaft portion. In an embodiment the end edge is substantially orthogonal to the center axis of the access port and/or to tangent to the access port at the access port exit. In an embodiment the end edge has an angle of larger than 90 degrees to the center axis and/or to tangent to the access port at the access port exit, such as an angle of from 100 to 125 degrees to the center axis and/or to tangent to the access port at the access port exit.

The cannula assembly kit may comprise several projectors and/or several pattern generating members.

In an embodiment the pattern generating member comprises two or more projectors wherein the pattern light source is operatively connected to the projectors for projecting light patterns. At least the projectors of the pattern generating member are configured to be at least temporarily fixed to the cannula shaft portion of the cannula, preferably at a distance from each other, such as at the end edge at diagonal sides of the distal access port exit.

The pattern light source may comprise a splitter and/or a filter splitting and or filtering the light into two or more fractions for said respective projectors, where said two or more light portions may be equal or different e.g. with respect to power, wavelengths, wavelength profiles. The two or more projectors may be equal or different from each other e.g. with respect to pattern shape or size.

In an embodiment the cannula assembly kit comprises two or more pattern generating members. The two or more pattern generating members may be equal or different from each other e.g. with respect to power, wavelengths, wavelength profiles pattern shape or size.

In an embodiment the cannula shaft portion comprises an access section adapted to be inserted through a surgical incision for allowing a surgical instrument to be inserted through the access port, wherein the access section is at least partially rigid, preferably the entire access section of the cannula shaft portion or the entire cannula shaft portion is substantially rigid. The rigidity of the cannula shaft portion ensures that when the cannula shaft portion is subjected to a tilting movement—e.g. by tilting of an instrument inserted into the access port—the projector will be moved in a correlated way and thereby resulting in a correlated change of the reflections of the projected light pattern which can be imaged onto a screen or transmitted to a robot via a camera e.g. mounted to or integrated with the cannula and/or a camera of a scope.

The recorded signal may preferably be transmitted in real time speed to ensure that the time delay becomes as small as possibly.

The term “access section” is used to denote the length section of the cannula shaft portion, which is adapted to be fully or partly inserted into the incision. It should be noted that a rigid section may comprise one or more layers, e.g. seals of non-rigid material.

In an embodiment at least said access section is collapsible by comprising a seal and or an isolation which collapses when the access port is free of an inserted instrument, to thereby prevent gas escape via the access port and thus prevent deflation of the abdominal or other surgical cavity inside the patient.

In an embodiment at least the access section is collapsible by being of a collapsible material, such at least at the access section is at least partly collapsed when the access port is free of an inserted instrument.

In an embodiment the cannula shaft portion comprises an access section adapted to be inserted through a surgical incision for allowing a surgical instrument to be inserted through the access port, wherein the access section is collapsible. Advantageously at least the access section of the cannula shaft portion is of a non-rigid material, such as an elastomer e.g. rubber.

The rigidity is determined at 25° C.

In principle, the cannula shaft portion may be straight or bent. Where the cannula shaft portion is substantially rigid, it is desired that the cannula shaft portion is relatively straight or optionally bent in a relatively soft curve.

Where the cannula shaft portion is straight, the access port will usually be straight as well.

In an embodiment the pattern generating member is detachable from the cannula shaft portion.

Preferably at least the projector of the pattern generating member is configured to be temporarily fixed to the cannula shaft portion by a click lock, a sleeve lock, a screw lock, a turn lock, a wedge lock or combinations thereof.

Advantageously the pattern light source is not fixed or adapted to be fixed to the cannula shaft portion. In an embodiment the pattern light source is fixed or adapted to be fixed to the flange portion of the cannula. The operative connection can in principle be any kind of wave guiding element or elements, such as an optical fiber, one or more lenses, mirrors, splitters, collimators, amplifiers or any other suitable optical element. The optical connection between the pattern light source and the projector is preferably provided by an optical fiber.

Where only the projector is mounted to the cannula shaft portion, the remaining part of the pattern generating member including the pattern light source may be reused without requiring sterilization.

In an embodiment at least the projector and the pattern light source of the pattern generating member are temporarily fixed to the cannula by a sleeve.

In an embodiment all elements of the pattern generating member are temporarily fixed to the sleeve. The elements of the pattern generating member comprise the projector and the pattern light source and optional power source and/or one or more controlling elements such as the pattern light source control unit described below.

In an embodiment at least the projector of the pattern generating member is permanently fixed to the cannula.

In an embodiment the pattern light source and an optional battery are fixed or adapted to be fixed to the cannula shaft portion.

In an embodiment the pattern light source and an optional battery are arranged in an external light source unit and are optically connected to the projector e.g. via an optical fiber, directly connected or by use of free space optics.

In an embodiment the pattern light source is adapted to be arranged at a distance to the projector, the pattern light source is preferably incorporated into a pattern light source housing arranged to be positioned at a distance to the cannula and advantageously connected to the projector via connection means comprising an optical fiber, preferably the optical fiber is protected by a polymer cover.

In an embodiment at least the projector of the pattern generating member is incorporated in or mounted to a sleeve. The sleeve preferably comprises a sleeve end edge portion comprising the projector. The sleeve is configured to be mounted onto the cannula shaft portion. Optionally the sleeve constitutes an outer and/or an inner seal for minimizing undesired gas leak. The sleeve is advantageously fixed or fixable to the flange portion. In an embodiment the pattern light source is incorporated in or mounted to a sleeve at its proximal end where the sleeve is mounted to the flange portion.

The sleeve may comprise any material including polymer material and/or metal. Preferably the sleeve has an outer surface which is hydrophilic and advantageously has a low friction. In an embodiment the sleeve comprises a coating for reducing friction e.g. a coating of PTFE or parylene. In an embodiment the surface of the sleeve has been subjected to a plasma treatment and/or chlorination.

Advantageously the sleeve is of elastomer, such as one more thermoplastic elastomers, rubber and/or silicone. Preferred materials comprise polyisoprene, silicone, butyl-ethylene propylene (diene) polymer and/or styrene butadiene rubber.

In an embodiment the cannula comprises a mounting through hole for mounting the projector, preferably the mounting through hole extends through the cannula shaft portion such that the projector can be mounted at or adjacent to the distal end of the cannula shaft portion. Thereby the projector can be mounted via said mounting through hole after the cannula has been inserted through a surgical incision.

In an embodiment the sleeve comprises a mounting through hole for mounting the projector prior to or after the cannula has been inserted through a surgical incision.

In an embodiment at least the projector of the pattern generating member is permanently fixed to the cannula shaft portion, preferably the projector is integrated with the cannula to form an integrated cannula assembly.

The pattern light source can in principle be any kind of light source capable of providing a desired pattern. The light source may be a coherent light source or an incoherent light source.

The term “coherent light” is herein used to denote laser light whereas “incoherent light” includes any non-laser light irrespectively of its degree of coherence. Incoherent light with a relatively high degree of coherence (sometimes called partially coherent light) is often preferred because the coherent light provides a highly bright pattern, while the incoherent light source generally can be obtained at a much lower cost than coherent light.

In an embodiment the pattern light source is a coherent light source, such as a semiconductor light source, such as a laser diode and/or a VCSEL light source.

In an embodiment the pattern light source is an incoherent light source, preferably the light source is a semiconductor light source, such as a light emitting diode (LED).

Advantageously, the light pattern is generated by at least one laser and/or LED. Lasers and LEDs (light emitting diodes) are advantageous as they can generate light patterns that are well defined and it is possible to choose the wavelength and thus color such that the pattern is enhanced in the remote vision, for example such that the light pattern is clearly visible and enhanced on the monitor and/or easily detectable for computer recognition, decoding and/or vision procession.

The pattern light source advantageously has a relatively narrow band width thereby providing a bright light in the narrow bandwidth, while simultaneously emitting a relatively low light energy. It is advantageous both to avoid undesired heating of the surgical target site and simultaneously have low risk of blinding and/or result in undesired side or error reflections which may distort the recording by the camera.

In an embodiment the pattern light source has a band width (full width at half maximum—FWHM) of up to about 50 nm, such as from 1 nm to about 40 nm. Preferably the narrow band width of the pattern light source is about 25 nm or less, such as about 10 nm or less.

In an embodiment the pattern light source is a broad band light source such as a supercontinuum light source e.g. spanning at least an octave within the bandwidth range from 400 nm to 2600 nm. Above 2600 nm light transmitted in a silica fiber will be strongly attenuated.

In an embodiment the pattern light source is configured for emitting at least one electromagnetic wavelength within the UV range of from about 10 nm to about 400 nm, such as from about 200 to about 400 nm.

In an embodiment the pattern light source is configured for emitting at least one electromagnetic wavelength within the visible range of from about 400 nm to about 700 nm, such as from about 500 to about 600 nm.

In an embodiment the pattern light source is configured for emitting at least one electromagnetic wavelength within the IR range of from about 700 nm to about 1 mm, such as from about 800 to about 2500 nm.

In an embodiment the pattern light source is configured for emitting two or more distinguished wavelengths or wavelength bandwidths and advantageously the pattern light source is configured for switching between said distinguished wavelengths or wavelength bandwidths.

Light in the lower wavelengths e.g. below 600 nm requires relatively high power in order to be visually distinguished from illuminating light emitted to light up the area under surgery—usually emitted from a scope, such as an endoscope.

In an embodiment the pattern light source comprises at least one wavelength within the visible range.

In an embodiment the pattern light source comprises at least one wavelength within the invisible range, such as the UV or the IR range. Where the pattern light source comprises wavelengths in the invisible range, such wavelengths are advantageously detected by the camera system and converted to a visible wavelength for displaying to the operator e.g. by digital processing.

In an embodiment the pattern generating member comprises two or more pattern light sources having equal or different bandwidths, wherein the two or more pattern light sources preferably are operatively connected to the projector.

the two or more pattern light sources can be operated independently of each other i.e. they can independently be switched on and off e.g. using a non-hand held unit or by a unit incorporated into the flange portion.

In an embodiment the two or more pattern light sources can be connected to separate projectors.

Generally, it is desired that the pattern light source (or sources) can be switched on and off and optionally be modified in wavelengths and/or intensity, using a pattern light source control unit. In an embodiment the pattern light source control unit is a non-hand held unit, such as a pedal or a voice activated control unit—thereby in a simple manner the operator can control the light pattern. In an embodiment the pattern light source control unit is incorporated into the flange portion.

In an embodiment the pattern light source (or sources) is controlled by a robot—e.g. by being part of the robot. The pattern light source control unit may advantageously be computer controlled.

Advantageously the pattern light source is arranged to provide a pattern output power, which is sufficient to generate a visible pattern, but not too high such that an undesired amount of heat may be generated. Preferably the pattern light source is arranged to provide a pattern output power up to about 100 mW such as at least about 0.1 mW, such as from about 1 to about 100 mW, such as from about 3 mv to about 50 mW. Preferably the pattern output power is adjustable. The pattern output power is determined as the output power of the projector.

Advantageously the pattern light source is tunable in wavelength and/or power and the cannula assembly kit comprises a regulator for tuning the pattern light source, preferably such that movements of a surgical instrument inserted through the access port trigger the regulator to a coordinated tuning of the pattern generating member. The tuning is advantageously performed such that movements in the distal towards proximal direction or vice versa of a surgical instrument inserted through the access port trigger the regulator to a coordinated tuning of the pattern generating member. In an embodiment the regulator is a tunable button arranged at an inner wall of the cannula shaft portion such that movement of a surgical instrument in the distal towards proximal direction or vice versa tunes the light intensity of the pattern light source up and down and/or changes the wavelengths of the pattern light source. In an embodiment where the pattern light source (or sources) is controlled by a robot the robot may advantageously control or comprise the surgical instrument inserted through the access port and the regulator for tuning the pattern light source may advantageously also be part of or at least controlled by the robot.

Advantageously the projector of the pattern generating member comprises a phase optic element, a spatial light modulator, a multi-order diffractive lens, a holographic lens, a mirror arrangement, a computer regulated optical element, and/or a computer regulated mechanically optical element e.g. a mems (micro-electro-mechanical) element.

The phase optic element may advantageously be a diffractive optic element (DOE).

In an embodiment the phase optics element is capable of producing an image having periodic intensity distribution.

Diffractive optic elements are well known in the art and may for example utilize a surface with a complex microstructure for its optical function. The micro-structured surface relief profile has two or more surface levels. The surface structures are either etched in fused silica or other glass types, or embossed in various polymer materials. Additionally, diffractive optics can realize almost the same optical functions as refractive optics such as lenses, prisms or aspheres, but they are much smaller and lighter. DOEs are not limited to laser applications; partially coherent light from LEDs or other light sources can also be modulated.

In an embodiment the DOE is as described in US 2013/0038836 e.g. as shown in FIG. 1 and/or as described in section [0015] of US 2013/0038836.

In an embodiment the diffractive optic elements comprise a “multi-order diffractive” lens, such as a conventional diffractive-optic lens utilizing a single diffraction order in which the optical power of the lens is directly proportional to the wavelength of light.

The projector may comprise any type of beam manipulating element for providing the desired pattern e.g. one or more lenses and/or mirrors and/or splitters and/or filters and/or collimators.

In an embodiment the projector comprises a spatial light modulator. The spatial light modulator is configured for modulating the light pattern for example by modulating the transparency of a pattern cover e.g. by a computer modulation. In an embodiment the spatial light modulator is arranged for modulating the intensity and/or the phase of the light from the pattern light source to thereby modulate the emitted light pattern.

In order to ensure that the cannula can be inserted through a desired small incision it is generally desired that the part of the pattern generating member to be mounted to the cannula shaft portion prior to insertion into an incision is relatively small.

Advantageously the projector of the pattern generating member has a maximally extending area perpendicular to the center axis of the access port when the pattern generating member is fixed to the cannula shaft portion, which maximally extending area is up to about 8 cm2, such as up to about 4 cm2, such as up to about 2 cm2, such as from about 0.01 to about 1 cm2, such as from about 0.1 to about 0.5 cm2. Preferably the projector of the pattern generating member is configured to be at least temporarily fixed at the end edge in the vicinity of the distal access port exit and the projector is preferably shaped such that the projector does not extend laterally beyond the end edge or up to 5 mm laterally beyond the end edge.

In an embodiment the projector of the pattern generating member has a projector face from where the light is to be emitted and the projector is pivotable, so it can be pivotally unfolded from a first folded position where the projector face is not facing in the distal direction to a second position where the projector face is facing in the distal direction. Thereby the cannula can be inserted into an incision when the projector is in a first folded position and there after the projector can be unfolded to its second position. Optionally the unfolding can be provided by triggering a release button at the inner wall of the cannula shaft portion e.g. by the surgical instrument—e.g. by a tilting of the surgical instrument—after the cannula has been inserted through the incision such that the projector is unfolded to its second position e.g. by a spring mechanism.

The pattern may have any desired shape.

In an embodiment the projector is fixed or adapted to be fixed to the cannula shaft portion such that the pattern remains substantially stationary when the surgical instrument is subjected exclusively to a circumferential movement with the longitudinal axis of the surgical instrument.

In an embodiment the projector when fixed to the cannula shaft portion is configured to emitting a pattern, which pattern when projected to a surface orthogonal to the center axis of the access port has at most 10 fold rotational symmetry, preferably the pattern has at most 8 fold rotational symmetry.

Such pattern which is not fully rotational symmetrical but has up to 10 fold rotational symmetry gives the operator an even better information about the position of the cannula relative to the surgical site.

In an embodiment the projector of the pattern generating member is configured to emit a pattern comprising an arch shape, ring or semi-ring shaped lines, a plurality of angled lines and/or a coded structured light configuration. In an embodiment the pattern comprises a grid of lines, e.g. a crosshatched pattern optionally comprising substantially parallel lines when emitted to a planar surface.

The changes in the grid lines due to lateral movements of the surgical instrument can for example be used to deduce the contours of the body cavity such as projected surface and/or the contours and/or topographic shape of the surgical field. The changes in the angle and distance between crossing and/or parallel grid lines during movement(s) of the surgical instrument can for example be used to determine the orientation of the cannula and thus the surgical instrument.

The phrases “surgical field”, “surgical site” and “surgery target site” are herein used interchangeably.

In an embodiment the light pattern comprises a plurality of light dots. When the surgical instrument is moved, the position and/or the distance between the dots will change, which enhances the operator's ability even further to deduce the position of the cannula assembly, the surgical instrument and the area contours of the surgical field.

In an embodiment of the pattern generating member is configured to emit a pattern comprising a coded structured light configuration comprising a plurality of light dots with different shapes and/or sizes arranged in a preselected configuration. The pattern comprising a coded structured light configuration is in particular suitable for determining a topographic shape of the target surface.

Patterns comprising coded structured light configurations are for example described in “Pattern codification strategies in structured light systems” by Salvi et al. Pattern Recognition, Volume 37, Issue 4, April 2004, Pages 827-849.

In an embodiment the projector fixed to the cannula shaft portion is configured to emit a pattern which pattern, when projected to a surface perpendicular to the longitudinal axis of the body portion of the surgical instrument, comprises a plurality of angled lines. Advantageously the pattern comprises a grid of lines, such as a grid comprising one or more sets of parallel lines.

Where the pattern has an angled lines when projected to a surface orthogonal to the center axis of the access port, a tilting of the surgical instrument inserted into the access port can for example be observed by a change of such angled lines e.g. by a deformation of one or more of the lines, by change of line angles and/or by change of distance between lines.

The pattern is advantageously sufficiently large to ensure good visual perception of the cannula/projector? surgical instrument and movement thereof.

At the same time, since the projector is fixed to the cannula shaft portion the risk of direct contact between the projector and tissue during surgery is relatively small and it has been found that for most procedures the projector requires less cleaning during minimally invasive surgery than an endoscope.

In an embodiment the projector of the pattern generating member is configured to emit a pattern, which pattern when emitted towards a plane surface at a distance of about 80 mm from the distal end of the cannula shaft portion and normal to a center axis of the cannula shaft portion, has a grid area of up to about 225 cm², such as of up to about 100 cm², such as of up to about 9 cm².

The flange portion comprises a handle part, the flange portion comprising means for being temporally fixed to an obturator.

In an embodiment the cannula comprises two or more access ports through the flange portion and the cannula shaft portion. Thereby several surgical instruments can be inserted simultaneously.

In an embodiment the cannula comprises two or more cannula shaft portions and an access ports through the flange portion and the cannula shaft portions suitable for inserting a surgical instrument through each of the respective access ports.

In an embodiment the cannula assembly kit comprises a cleaning element for cleaning the projector.

In an embodiment the cleaning element is in the form of a wiping element arranged for wiping and/or washing the projector. In an embodiment the cleaning element is in the form of a spray element arranged for spraying and/or blowing the projector with a fluid such as gas or liquid. An example of a suitable cleaning element is as the cleaning device described in U.S. Pat. No. 8,397,335.

In an embodiment the cannula is adapted for being handled by a surgeon—i.e. to be mounted in an incision of a patient to provide the access port to the surgical site.

In an embodiment the cannula is adapted for being maneuvered by a robot—i.e. to be mounted in an incision of a patient using a robot to provide the access port to the surgical site.

In an embodiment the cannula is a part of the robot.

In an embodiment the invention also comprises a trocar assembly kit for use in minimally invasive surgery. The trocar assembly kit comprises a cannula assembly as described above and an obturator. The obturator may in principle be any kind of obturator configured to be used with a cannula.

The obturator has a distal end and a proximal end and comprises a head portion at its proximal end, a tip portion at its distal end and a rigid obturator shaft portion extending between the head portion and the tip portion, wherein the cannula and the obturator are correlated to each other such that the tip portion of the obturator can be instead through the access port of the cannula and the head portion of the obturator can be temporally fixed to the flange portion of the cannula, preferably such that a seal is formed in the access opening between the cannula and the obturator.

Advantageously the obturator comprises a projector protection arrangement correlated with the projector of the cannula assembly kit to at least partly cover the projector when the cannula assembly kit and the obturator are in an assembled state. Thereby the projector can be protected by the projector protection arrangement during insertion of the trocar assembly through an incision. The projector protection arrangement is advantageously arranged to be at least partly passed into a cavity of the obturator upon withdrawing of the obturator from said cannula access port.

The cannula assembly kit and the obturator are in an assembled state when the tip portion of the obturator is inserted substantially fully through the access port of the cannula shaft portion, and the cannula assembly kit and the obturator are disassembled upon withdrawing of the obturator from said cannula access port.

In an embodiment the projector protection arrangement is arranged to be pivotally folded from a first position where it, at least partly covers the projector to a second position where it at least partly is passed into a cavity of the obturator. The folding from the second position to the first position may for example be performed manually after having inserted the tip portion of the obturator substantially fully through the access port of the cannula shaft portion and the folding from the first position to the second position may for example be performed simply by withdrawing the obturator from the access port and/or by releasing a holding mechanism temporarily holding the projector protection arrangement in the first position.

In an embodiment the projector protection arrangement is arranged to be radially displaced from a first position where it, at least partly covers the projector to a second position where it at least partly is passed into a cavity of the obturator. The radial displacement may for example be provided by a spring arrangement and/or a holding mechanism temporarily holding the projector protection arrangement in one of the first position and the second positions.

In an embodiment the invention also comprises a sleeve assembly suitable for a cannula assembly kit as described above. The sleeve assembly comprises a sleeve and a pattern generating member. The pattern generating member comprises a pattern light source and a projector, wherein the pattern light source is operatively connected to the projector for projecting a light pattern. At least the projector of the pattern generating member is configured to be at least temporarily and rigidly fixed to the sleeve, the sleeve preferably comprises a sleeve end edge portion comprising the projector.

The sleeve may advantageously be as described above.

In an embodiment the sleeve is configured to substantially fully cover at least a cannula shaft portion of a cannula. In an embodiment the sleeve is configured to cover at least a part of a cannula flange portion of the cannula.

In an embodiment the minimally invasive surgery system comprises a cannula assembly kit preferably as described above, a surgical instrument, a camera and a computer system.

The camera may be a mono camera or a stereo camera. In an embodiment the minimally invasive surgery system comprises two or more camera adapted for recording image data. The minimally invasive surgery system may be configured to combining or multiplexing said image data.

In an embodiment the camera is mounted to or integrated with the cannula e.g. as described above.

The camera may advantageously comprise a charge-coupled device (CDD) image sensor, or a complementary metal-oxide-semiconductor (CMOS) image sensor.

In an embodiment the camera is mounted to a scope. A Scope is herein used to mean any suitable scope, such as an endoscope, a laparoscope anarthroscope, a thoracoscope, a gastroscope, a colonoscope, a laryngoscope, a broncoscope, a cystoscope or a combination thereof In an embodiment the scope is an endoscope. In an embodiment the scope is a laparoscope.

Advantageously the computer is configured for generating a 3D model of the surgical surface by using wide baseline triangulation between the camera and the cannula assembly thereby generating a 3D model in the form of a point cloud. The angle between the camera and the cannula assembly and in particularly the center axis of the projected light pattern may be stationary or variable and the computer may preferably be configured for determining the angle and compensate therefore. The system may e.g. comprise one or more further sensors for determining the angle between the camera and the cannula assembly. The angle between the camera and the cannula assembly and in particularly the center axis of the projected light pattern may for example be at least 5 degrees, such as from 10 to 50 degrees, such as from 25 to 45 degrees.

In an embodiment the minimally invasive surgery system comprises two or more cameras, such as at least one camera mounted to or integrated with the cannula and at least one camera mounted to or integrated with a scope.

In an embodiment the computer system is programmed to determining a spatially position and orientation of the projector. This may for example be performed by ensuring that the project pattern is a coded pattern e.g. an asymmetrical pattern where different areas of the projected pattern seen in cross sectional view may be uniquely identified to determine a spatially position and orientation of the projector.

The minimally invasive surgery system may further comprise one or more illuminating element, such as an illuminating element mounted to or integrated with the scope.

The minimally invasive surgery system may additionally comprise one or more sensors which may be used in the generation of minimally invasive surgery data and/or performing a minimally invasive surgery. Such one or more sensors may include light emitting based sensors, mechanical sensors, electrical sensors and etc. In an embodiment the one or more sensors comprises position tracking sensor(s), accelerometer(s), gyroscope(s) and/or other motion-sensing devices.

It is advantageous that the projected light pattern of the cannula assembly kit comprises at least one wavelength not comprised by the optional other illuminating light sources and/or sensor light sources.

The surgical tool of the minimally invasive surgery system is advantageously selected from a grasper, a suture grasper, a cutter, a sealer, a stapler, a clip applier, a dissector, scissors, shears, a suction instrument, a clamp instrument, an electrode, a coagulation device, a curette, ablators, scalpels, a needle holder, a needle driver, a spatula, forceps, a biopsy and retractor instrument or a combination thereof.

The computer system may comprise hardware and software for collecting minimally invasive surgery data and/or for performing minimally invasive surgery.

The computer system may comprise one or more hardware elements which are or are adapted to be in data communication.

In an embodiment the computer system is in data communication with the camera to receive image data from the camera. The computer system is programmed to determining real time position data of the surgical instrument, to determining real time topography data of a surface reflecting the light pattern emitted by the cannula assembly kit and/or to determining real time contours of a surface reflecting the light pattern emitted by the cannula assembly kit.

In an embodiment the computer system is configured to transmitting the determined data to a robot, a database and/or a monitor for being displayed.

In an embodiment the surgical instrument forms part of the robot or is adapted for being maneuvered by the robot. The computer system is preferably configured to transmitting the determined data to the robot. In an embodiment the computer system or at least a part of the computer system forms part of the robot.

In an embodiment the cannula assembly kit is adapted for being controlled by a computer or forms part of the computer.

In an embodiment the surgical instrument forms part of a robot or is adapted for being maneuvered by a robot and the computer system is configured for determining a spatially position of the instrument and based at least partly on said real time topography data and said spatially position of the instrument to control the robot to perform movements of the instrument.

In an embodiment the invention also relates to a method of performing a minimal invasive surgery of a target surgical site in an internal body structure below a skin area of a patient. In an embodiment the method comprises,

-   -   providing an access port to the surgery target site comprising         providing an incision through the skin area inserting a cannula         assembly kit as described above,     -   inserting a surgical instrument through the access port,     -   inserting a camera element through the access port or through an         additional access port to the surgery target site,     -   providing that the projector if the cannula assembly kit is         emitting a light pattern,     -   recording image data of the light pattern reflected from the         surgery target site by the camera, and     -   moving the surgical instrument for performing the minimal         invasive surgery while simultaneously receiving feedback based         on the recorded image data.

In an embodiment the method comprises,

-   -   providing an access port to the surgery target site comprising         providing an incision through the skin area inserting a cannula         assembly kit with a camera as described above,     -   inserting a surgical instrument through the access port,     -   providing that the projector if the cannula assembly kit is         emitting a light pattern,     -   recording image data of the light pattern reflected from the         surgery target site by the camera, and     -   moving the surgical instrument for performing the minimal         invasive surgery while simultaneously receiving feedback based         on the recorded image data.

In an embodiment the method comprising performing the minimally invasive surgery by using the minimally invasive surgery system as described above.

The method of performing a minimal invasive surgery may be performed by an operator i.e. a surgeon and/or a robot.

For example in an embodiment a surgeon is performing an incision and inserting the cannula assembly kit and a robot is performing the remaining method steps.

In an embodiment the entire method of performing a minimal invasive surgery is performed by a robot. The recorded image data may simultaneously be transmitted to a monitor for being displaced such than an observer, such as a supervisor, a surgeon and/or a trainee can observe the minimally invasive surgery performed by the robot.

All features of the inventions including ranges and preferred ranges can be combined in various ways within the scope of the invention, unless there are specific reasons not to combine such features.

BRIEF DESCRIPTION OF EXAMPLES

Preferred embodiments of the invention will be further described with reference to the drawings.

FIG. 1a is a schematic view of an embodiment of a cannula assembly kit.

FIG. 1b is a schematic view of an embodiment of an obturator adapted to be used together with the cannula assembly kit of FIG. 1 a.

FIG. 1c and FIG. 1d are schematic views of a trocar assembly kit comprising the cannula assembly kit of FIG. 1 and the obturator of FIG. 2 is partly or fully in an assembled state.

FIG. 2 is a schematic view of an embodiment of a cannula assembly kit, where the shaft portion of the cannula comprises a mounting through hole through which the projector has been mounted.

FIG. 3 is a schematic view of an embodiment of a cannula assembly kit comprising a sleeve.

FIG. 4 is a schematic view of an embodiment of a cannula assembly kit with a relatively large flange portion for comprising the pattern light source.

FIG. 5 is a schematic view of a distal end portion of an assembled trocar assembly kit, where the obturator comprises a projector protection arrangement.

FIG. 6 is a schematic view of an embodiment of a cannula assembly kit during use in a surgical procedure seen from outside the body cavity.

FIG. 7 is a schematic view of an embodiment of a cannula assembly kit during use in a surgical procedure seen in a cross-sectional view through the body cavity.

FIG. 8 is a schematic view of an embodiment of a cannula assembly kit configured for emitting a bullseye shaped pattern.

FIG. 9 is a schematic view of an embodiment of a cannula assembly kit with a bent cannula shaft portion.

FIG. 10 is a schematic view of an embodiment of a cannula assembly kit where the cannula comprises two cannula shaft portions and one cannula flange portion.

FIG. 11 is a schematic view of another cannula assembly kit where the cannula comprises two cannula shaft portions and one cannula flange portion.

FIG. 12 is a schematic view of an embodiment of a cannula assembly kit where the cannula comprises two cannula flange portions and one cannula shaft portion.

FIG. 13 is a schematic illustration of an embodiment of a minimally invasive surgery system of the invention where the projected light pattern comprises a coded structured light configuration comprising a plurality of light dots with different sizes.

FIG. 14 is a schematic illustration of an embodiment of a minimally invasive surgery system where the projected light pattern comprises a coded structured light configuration comprising a plurality of light dots with different shapes and sizes.

FIG. 15 is a schematic illustration of an embodiment of a minimally invasive surgery system where the projected light pattern comprises a crosshatched pattern

FIG. 16 is a schematic illustration of an embodiment of a minimally invasive surgery system where the projected light pattern comprises a plurality of parallel lines.

FIG. 17a illustrates a part of a minimally invasive surgery system.

FIG. 17b illustrates a procedure performed using the minimally invasive surgery system of FIG. 17 a.

FIG. 18a illustrates a part of the minimally invasive surgery system of FIG. 17 a.

FIG. 18b illustrates a part of minimally invasive surgery system of FIG. 18a and a procedure performed using the minimal invasive system of FIG. 17 a.

FIG. 19 illustrates a procedure performed by a minimally invasive surgery system involving a number of sub-procedures.

FIGS. 20a and 20b illustrate an operation of a surgical tool of a minimally invasive surgery system.

The figures are schematic and are not drawn to scale and may be simplified for clarity. Throughout, the same reference numerals are used for identical or corresponding parts.

FIG. 1a illustrates an embodiment of a cannula assembly which may form part of a minimally invasive surgery system. The cannula assembly kit comprises a cannula 1 and a pattern generating member wherein only the projector 2 is shown. The cannula has a distal end D and a proximal end P and comprises a flange portion 4 at its proximal end and an elongate cannula shaft portion 3 extending from the flange portion 4 to its distal D end and an access port A through the flange portion 4 and the elongate cannula shaft portion 3, such that a surgical tool of a surgical instrument can be inserted through the access port. The pattern generating member comprises a not shown pattern light source and a projector 2 at least temporarily fixed to the cannula shaft portion 3 of the cannula. The cannula flange portion 4 comprises an insufflation port 5 for insufflating the body cavity.

The obturator and the cannula assembly kit of FIG. 1 are correlated to each other. The obturator 9 shown in FIG. 1b has a distal end D and a proximal end P and comprises a head portion 6 at its proximal end, a tip portion 8 at its distal end and a rigid obturator shaft portion 7 extending between said head portion 6 and said tip portion 8. The tip portion can be bladed or non-bladed.

The obturator of FIG. 1b and the cannula assembly kit of FIG. 1 are correlated to each other such that the obturator can be inserted into the access port A of the cannula 1. In FIG. 1c the obturator 9 is partly inserted into the access port A of the cannula 1. In FIG. 1d the obturator 9 is fully inserted into the access port A of the cannula 1 to thereby assemble the trocar assembly kit.

The cannula assembly kit shown in FIG. 2 comprises a cannula and a pattern generating member wherein only the projector 12 is shown. The cannula comprises a flange portion 14 and an elongate cannula shaft portion 13 extending from the flange portion 14 to its distal end and an access port A. At its distal end the cannula shaft portion 13 has an access port exit 13 a and comprises an end edge 13 b in the vicinity of said distal access port exit 13 a.

The shaft portion 13 of the cannula comprises a mounting through hole 12 a indicated on the drawing with dotted lines. The projector 12 has been mounted via the mounting through hole 12 a and a not shown optical fiber extends through the mounting through hole 12 a for transmitting light to the projector 12.

The cannula assembly kit shown in FIG. 3 comprises a cannula and a pattern generating member wherein only the projector 22 is shown. The cannula comprises a flange portion 24 and an elongate cannula shaft portion 23 extending from the flange portion 24 to its distal end and an access port A.

The shaft portion 23 and the flange portion 24 are covered by a sleeve 26 which is mounted to the cannula. The projector 22 is mounted to or integrated in the sleeve 26 and the sleeve also comprises a fiber covering line 22 a comprising a not shown optical fiber arranged for transmitting light to the projector 22.

The cannula assembly kits shown in FIG. 4 comprises a flange portion 34 and an elongate cannula shaft portion 33 extending from the flange portion 34 to its distal end and an access port A. The cannula assembly kit also comprises a not shown pattern generating member. The rays R indicate that the not shown projector is positioned at the distal end of the cannula shaft portion 33. The cannula flange portion 34 is relatively large such that a not shown light source and/or battery can be incorporated into the cannula flange portion 34.

The distal end portion of an assembled trocar assembly kit shown in FIG. 5 comprises distal end portions of the correlated cannula assembly kit and obturator. The cannula assembly kit comprises a cannula shaft portion 43 and a projector 42 arranged for projecting a light pattern. The obturator comprises a rigid obturator shaft portion 47 and a tip portion 48. The obturator further comprises a projector protection arrangement 47 a correlated with the projector 42 of the cannula assembly kit to at least partly cover the projector 42, such that the projector is at least partly projected during the insertion during surgery. In a not shown modified embodiment the projector protection arrangement is shaped to align with the shape of the tip portion of the obturator such that there will be a more gradually increase of the diameter of the assembled trocar assembly kit from the tip portion of the obturator to the cannula shaft portion of the cannula assembly kit.

When the obturator is withdrawn from the access port of the cannula assembly kit, the projector protection arrangement 47 a will at least partly be passed into a cavity of the obturator, such that the projector protection arrangement 47 a is not blocking for the withdrawal. The projector protection arrangement 47 a may for example be pivotally folded into a cavity of the obturator, by folding towards the tip portion 48.

FIG. 6 and FIG. 7 show a cannula assembly kit in use during a surgical procedure. The figures show a body part of a patient in surgery, where an incision I is made through the skin 50 of the patient, the cannula assembly kit comprises a shaft portion 53 and a flange portion 54, and the shaft portion 53 is inserted through the incision I. The cannula assembly kit comprises a pattern generating member comprising a projector from where a light pattern P in the form of rays R of light is emitted.

A surgical instrument comprising a handle portion 56, a body portion 57 and a surgical tool 58 is inserted through the access port of the cannula assembly kit and the pattern P is projected onto a surgical site 60.

It can be seen that when the surgical tool 58 of surgical instrument is subjected to a lateral movement and/or tilting movement the pattern will be moved in a correlated way, thereby providing information to the operator.

The pattern may for example be recorded by an image recorder on a scope inserted via the same or another incision through the skin.

The cannula assembly kit 61 shown in FIG. 8 comprises a not shown projector operatively connected to a light source and configured for emitting light rays R arranged to form a bullseye shaped pattern P. The various rings of the bullseye shaped pattern P could for example have different wavelength profile.

The cannula assembly kit shown in FIG. 9 comprises a cannula and a pattern generating member wherein only the projector 72 is shown. The cannula comprises a flange portion 74 and an elongate cannula shaft portion 73 extending from the flange portion 74 to its distal end and an access port A. The cannula shaft portion 73 is bent in a soft curve to thereby make is easier for an operator to insert the cannula shaft portion 73 through an incision of a patient. The cannula shaft portion 73 is for example pre-bent to the shown bending curve and is further bendable or flexible i.e. in unloaded condition the cannula shaft portion 73 is bent. In another embodiment the cannula shaft portion 73 is substantially rigid in the bent position.

At its distal end the cannula shaft portion 73 comprises an end edge 73 b and the projector 72 is mounted at the end edge 73 b and a not shown optical fiber is arranged to guide light along a channel 72 a in the wall of the cannula shaft portion 73.

The cannula assembly kit shown in FIG. 10 comprises a cannula and at least one pattern generating member wherein only the two projectors 82 are shown. The two projectors 82 can be of a common pattern generating member or they can be of separate pattern generating members.

The cannula comprises a flange portion 84 and a double cannula shaft portion 83, 83 a, 83 b. The double cannula shaft portion 83, 83 a, 83 b comprises a common shaft portion section 83 and two branch shaft portion sections 83 a and 83 b each comprising a distal access port section A, such that the cannula has a common access port section through the flange portion 84 and through the common shaft portion section 83 and two separate distal access port sections through said respective branch shaft portion sections 83 a and 83 b.

The cannula assembly kit shown in FIG. 11 comprises a cannula and at least one pattern generating member wherein only the two projectors 92 are shown. The two projectors 92 can be of a common pattern generating member or they can be of separate pattern generating members.

The cannula comprises a flange portion 94 and two cannula shaft portions 93 a, 93 b providing two access ports through the cannula flange portion 94.

The cannula assembly kit shown in FIG. 12 comprises a cannula and at least one pattern generating member wherein only the projector 102 is shown.

The cannula comprises two flange portions 104 a, 104 b and a double cannula shaft portion 104, 104 a, 104 b. The double cannula shaft portion 104, 104 a, 104 b comprises a common shaft portion section 104 and two branch shaft portion sections 104 a and 104 b. The respective branch shaft portion sections 104 a and 104 b are connected to the respective flange portions 104 a, 104 b and are merged in the common shaft portion section 104 in the distal end section of the cannula.

The minimally invasive surgery system shown in the respective FIGS. 13, 14, 15 and 16 comprises a cannula assembly kit 110, a surgical instrument 115, a camera 116 and a computer system 118.

The cannula assembly kit 110 comprises a flange portion 114, an elongate cannula shaft portion 117 and a projector 112 for projecting a light pattern at its distal end. An access port is provided via the cannula shaft portion 117.

The surgical instrument 115 comprises its actual operation tool 115 a at its distal end. The distal end comprising the operation tool 115 a is inserted through the access port of the cannula assembly kit 110.

The projector 112 projects a light pattern towards a distally arranged surface 111 and the reflected light pattern 113 is recorded by the camera 116. In use this distally arranged surface 111 will be a surgery site which may be very uneven as described above.

As the surgical instrument 115 is moved the cannula assembly kit will be moved accordingly and thereby also the projector 112 will be moved and the reflected pattern 113 will change accordingly at least when the surgical instrument 115 is subjected to tilting movements.

The camera records the reflected light and generates recorded image data. The recorded image data is transmitted to the computer system 118.

In the shown embodiment the computer system comprises a calibration unit for calibration of the camera, a processing unit comprising algorithms for 3D data set generation and decoding of the recorded and calibrated image data, a processing unit for determine topography data in real time and a PC for storing and/or displaying the determined topography data. The various units of the computer system 118 may be integrated in a common hardware box.

As described above the surgical instrument 115 may advantageously form part of a robot for performing the minimally invasive surgery and the computer system may provide feedback to the robot and/or at least a part of the computer system may be an integrated part of the robot.

In FIG. 17 the projected light pattern comprises a coded structured light configuration comprising a plurality of light dots with different sizes.

In FIG. 14 the projected light pattern comprises a coded structured light configuration comprising a plurality of light dots with different shapes and sizes.

In FIG. 15 the projected light pattern comprises crosshatched pattern

In FIG. 16 the projected light pattern comprises a plurality of parallel lines.

The minimally invasive surgery system shown in FIGS. 17a and 17b comprises a robot where only one robot arm is shown. The robot may comprise several arms. The robot arm comprises a number of joints J for bending, rotating, twisting and generally moving the robot arm. At its outermost section a surgical instrument and a cannula assembly is mounted. The surgical instrument is mounted to the robot arm via its mounting portion and the mounting portion can be displaced in a direction parallel to (coincident with) the axis of the cannula and the axis of the straight body portion of the surgical instrument. The cannula of the cannula assembly is inserted through an incision in the skin of a patient. The cannula assembly comprises a projector projecting a light pattern, which is reflected by the surgical surface as illustrated with the cross hatched pattern. A camera e.g. of an endoscope captures images of the reflected pattern and transmit image date to the computer system as illustrated in FIG. 17b . The image data is processed by the computer system using software algorithms for determining spatial position and orientation of the projector relative to the surgical surface e.g. distance B. Advantageously this determination is performed as real-time determinations monitoring the distance B during at least a part of a surgical procedure.

Top image of FIG. 18b is a close up illustration of the instrument and cannula assembly and it shows that the cannula is inserted through an incision in the skin of a patient.

Bottom image of FIG. 18b is a close up illustration of the surgical tool as it passes through the cannula and the distance A between the surgical tool tip and the cannula is indicated.

FIG. 18b further illustrates a procedure comprising 1) mounting the cannula assembly to the robot arm, 2) mounting the surgical instrument to the robot arm, 3) calibrating the displacement between the cannula and the distal surgical tool tip, 4) determining movements of the surgical tool e.g. by one or more sensors at the tool and/or by the computer system (where and if the computer system is configured for operating the surgical tool) and 5) continuously determining the distance A between the projector of the cannula and the distal tip of the surgical tool based on the displacement calibration and the data from the motion sensor

FIG. 19 illustrated a procedure performed by a minimally invasive surgery system involving a number of sub-procedures. A first sub-procedure is illustrated from image I to image II. Based on calibration data the computer calculate the relative position between the projector of the cannula assembly and the distal tip of the surgical tool—(distance A). This first sub-procedure corresponds to the procedure illustrated in FIG. 18b . A second sub-procedure is illustrated from image III to image IV. Based on camera images the computer calculates the position of the projector of the cannula assembly—(distance B). This first sub-procedure corresponds to the procedure illustrated in FIG. 18 a.

A third sub-procedure is illustrated from image V to image VI. Pair wise time correlated A and B distance determinations are combined. The computer calculates the distance between the surgical surface and the distal tip of the surgical tool (distance C). Thereby all distances A, B and C may be determined in real-time (B−A=C).

FIG. 20a illustrates an operation of a surgical tool of a minimally invasive surgery system. Only cannula assembly and parts of the surgical tool are shown. In the left hand image, the distance (c) between the distal tip of the surgical tool and the surgical surface is determined. In the right hand image it is illustrated that the distance (c) is updated in real-time based on acquired motion data representing the movement of the surgical tool.

The distance C between the distal tip and the surgical surface is determined as the distance B between the projector of the cannula assembly minus the distance A between the distal tool tip and the projector of the cannula.

In an embodiment The computer system is further configured for determining the orientation of the surgical instrument and/or surgical tool.

In a procedure as indicated in FIG. 20b , encoders and/or other sensors are applied to sense movements of the tool tip. Data representing the tool tip movements are transmitted to the computer system. The computer calculates the change in distances A, B, C (see FIG. 19) and orientation of the tool and/or pointing direction of the tip. The computer process the data and update in real-time at least the distance C between the distal tip of the surgical tool and the surgical surface. 

1-20. (canceled)
 21. A minimally invasive surgery system, comprising a robot comprising at least one movable robot arm; an elongate cannula detachably mounted to the robot arm, the cannula having a distal end and a proximal end with a lumen extending between the distal and proximal ends along a longitudinal axis of the cannula; a projector disposed on an outer surface of the cannula and configured to project a light pattern onto a tissue; and a computer system configured to: receive image data, in real time, characterizing an image of the light pattern projected onto the tissue, determine a spatial position of the cannula relative to the tissue based on the image data, determine an orientation of a distal end of a surgical tool of a surgical instrument disposed in the elongate shaft portion relative to the longitudinal axis of the cannula, and determine a distance between the distal end of the surgical tool and the tissue based on the determined spatial position of the cannula and the determined orientation of the distal end of the surgical tool.
 22. The minimally invasive surgery system of claim 21, wherein the determined spatial position of the cannula characterizes a distance between the distal end of the cannula and the tissue.
 23. The minimally invasive surgery system of claim 21, further comprising a camera configured to acquire the image of the light pattern, to generate the image data, and to transmit the image data in real time to the computer system.
 24. The minimally invasive surgery system of claim 23, wherein the camera is mounted to or integrated with the robot.
 25. The minimally invasive surgery system of claim 21, further comprising the surgical instrument, the surgical instrument being detachably mounted to the at least one movable robot arm.
 26. The minimally invasive surgery system of claim 21, wherein the computer system is configured to determine a real-time spatial position of a portion of the surgical instrument relative to the surgical surface from the determined spatial position of the cannula relative to the tissue and the determined distance between the cannula and the portion of the surgical instrument.
 27. The minimally invasive surgery system of claim 21, wherein the robot comprises at least one encoder configured for tracking real time movements of the surgical tool and for transmitting the tracked movements in real time to the computer system.
 28. The minimally invasive surgery system of claim 27, wherein the at least one encoder comprises at least one of a rotary or a linear encoder on the at least one robot arm.
 29. The minimally invasive surgery system of claim 27, wherein the at least one encoder is a mechanical encoder, a magnetic encoder, an optical encoder, a capacitive encoder, or a combination thereof.
 30. The minimally invasive surgery system of claim 21, wherein the robot comprises a tracking sensor configured for real time tracking of movements of the surgical tool
 31. The minimally invasive surgery system of claim 30, wherein the tracking sensor is a time-of-flight sensor, a magnetic sensors, or a structured light sensor.
 32. The minimally invasive surgery system of claim 21, wherein the computer system is configured to control movements of the at least one movable robot arm of the robot. 